code: def test_nlargest_multiindex_column_lookup(self):
      # Check whether tuples are correctly treated as multi-level lookups.
      # GH#23033
      df = pd.DataFrame(
          columns=pd.MultiIndex.from_product([["x"], ["a", "b"]]),
          data=[[0.33, 0.13], [0.86, 0.25], [0.25, 0.70], [0.85, 0.91]],
      )
  
      # nsmallest
      result = df.nsmallest(3, ("x", "a"))
      expected = df.iloc[[2, 0, 3]]
      tm.assert_frame_equal(result, expected)
  
      # nlargest
      result = df.nlargest(3, ("x", "b"))
      expected = df.iloc[[3, 2, 1]]
      tm.assert_frame_equal(result, expected)
  
file_path: pandas/pandas/tests/frame/methods/test_nlargest.py
imports: from string import ascii_lowercase
  import numpy
  import pytest
  import pandas
  import pandas._testing
  from pandas.util.version import Version
label_desc: Use image node_id 8 for calling the TestNLargestNSmallest obj's underlying member method code with example usage: obj.test_nlargest_multiindex_column_lookup() without return types